src/tui/app.rs

@@ -129,6 +129,16 @@ impl<'a> Widget for &mut App<'a> {
         self.explorer.render(horizontal[0], buf);
 
         self.draw_tabs(editor_layout[0], buf);
+
+        if let Some(editor) = self.editor.file_path.clone() {
+            let editor_abs = std::path::absolute(editor).unwrap();
+            if let Some(selected) = self.explorer.selected() {
+                let selected_abs = std::path::absolute(selected).unwrap();
+                if selected_abs.is_file() && selected_abs != editor_abs {
+                    self.editor.set_contents(&selected_abs).ok();
+                }
+            }
+        }
         self.editor.render(editor_layout[1], buf);
     }
 }
@@ -150,13 +160,14 @@ impl<'a> Component for App<'a> {
             match self.handle_key_events(key_event) {
                 Action::Quit => return Action::Quit,
                 Action::Handled => {
-                    dbg!(format!("Handled event: {:?}", self.id()));
+                    // dbg!(format!("Handled event: {:?}", self.id()));
                     return Action::Handled;
                 }
                 _ => {}
             }
         }
-        self.editor.handle_event(event);
+        self.explorer.handle_event(event.clone());
+        self.editor.handle_event(event.clone());
 
         // Handle events for all components.
         // for component in &mut self.components {

src/tui/editor.rs

@@ -17,7 +17,7 @@ use ratatui::widgets::{Block, Borders, Padding, Widget};
 pub struct Editor {
     pub state: EditorState,
     pub event_handler: EditorEventHandler,
-    file_path: Option<std::path::PathBuf>,
+    pub file_path: Option<std::path::PathBuf>,
 }
 
 impl Editor {
@@ -30,15 +30,16 @@ impl Editor {
     }
 
     pub fn set_contents(&mut self, path: &std::path::PathBuf) -> Result<()> {
-        let contents = std::fs::read_to_string(path)
-            .expect(&format!("Failed to read file contents: {}", path.display()));
+        if let Ok(contents) = std::fs::read_to_string(path) {
             let lines: Vec<_> = contents
                 .lines()
                 .map(|line| line.chars().collect::<Vec<char>>())
                 .collect();
             self.file_path = Some(path.clone());
             self.state.lines = Lines::new(lines);
-        Ok(())
+            return Ok(());
+        }
+        Err(anyhow::Error::msg("Failed to set editor file contents"))
     }
 
     pub fn save(&self) -> Result<()> {

src/tui/explorer.rs

@@ -1,18 +1,19 @@
-use crate::tui::component::Component;
+use crate::tui::component::{Action, Component};
 use anyhow::Result;
 use ratatui::buffer::Buffer;
-use ratatui::layout::{Alignment, Rect};
+use ratatui::crossterm::event::{Event, KeyCode, KeyEvent, MouseEvent, MouseEventKind};
+use ratatui::layout::{Alignment, Position, Rect};
 use ratatui::prelude::Style;
-use ratatui::style::Color;
-use ratatui::widgets::{Block, Borders, Widget};
+use ratatui::style::{Color, Modifier};
+use ratatui::widgets::{Block, Borders, StatefulWidget};
 use std::fs;
-use tui_tree_widget::{Tree, TreeItem};
-use uuid::Uuid;
+use tui_tree_widget::{Tree, TreeItem, TreeState};
 
-#[derive(Clone, Debug)]
+#[derive(Debug)]
 pub struct Explorer<'a> {
     root_path: std::path::PathBuf,
     tree_items: TreeItem<'a, String>,
+    tree_state: TreeState<String>,
 }
 
 impl<'a> Explorer<'a> {
@@ -20,6 +21,7 @@ impl<'a> Explorer<'a> {
         let explorer = Explorer {
             root_path: path.to_owned(),
             tree_items: Self::build_tree_from_path(path.to_owned()),
+            tree_state: TreeState::default(),
         };
         explorer
     }
@@ -36,8 +38,10 @@ impl<'a> Explorer<'a> {
                 if path.is_dir() {
                     children.push(Self::build_tree_from_path(path));
                 } else {
+                    if let Ok(path) = std::path::absolute(&path) {
+                        let path_str = path.to_string_lossy().to_string();
                         children.push(TreeItem::new_leaf(
-                        Uuid::new_v4().to_string(),
+                            path_str,
                             path.file_name()
                                 .expect("Failed to get file name from path.")
                                 .to_string_lossy()
@@ -46,9 +50,20 @@ impl<'a> Explorer<'a> {
                     }
                 }
             }
+        }
 
+        let abs = std::path::absolute(&path)
+            .expect(
+                format!(
+                    "Failed to find absolute path for TreeItem: {}",
+                    path.to_string_lossy().to_string()
+                )
+                .as_str(),
+            )
+            .to_string_lossy()
+            .to_string();
         TreeItem::new(
-            Uuid::new_v4().to_string(),
+            abs,
             path.file_name()
                 .expect("Failed to get file name from path.")
                 .to_string_lossy()
@@ -57,10 +72,9 @@ impl<'a> Explorer<'a> {
         )
         .expect("Failed to build tree from path.")
     }
-}
 
-impl<'a> Widget for &Explorer<'a> {
-    fn render(self, area: Rect, buf: &mut Buffer) {
+    pub fn render(&mut self, area: Rect, buf: &mut Buffer) {
+        StatefulWidget::render(
             Tree::new(&self.tree_items.children())
                 .expect("Failed to build tree.")
                 .style(Style::default())
@@ -76,7 +90,20 @@ impl<'a> Widget for &Explorer<'a> {
                         .title_style(Style::default().fg(Color::Green))
                         .title_alignment(Alignment::Center),
                 )
-            .render(area, buf);
+                .highlight_style(
+                    Style::new()
+                        .fg(Color::Black)
+                        .bg(Color::Rgb(57, 59, 64))
+                        .add_modifier(Modifier::BOLD),
+                ),
+            area,
+            buf,
+            &mut self.tree_state,
+        )
+    }
+
+    pub fn selected(&self) -> Option<&String> {
+        self.tree_state.selected().last()
     }
 }
 
@@ -84,4 +111,54 @@ impl<'a> Component for Explorer<'a> {
     fn id(&self) -> &str {
         "explorer"
     }
+    fn handle_event(&mut self, event: Event) -> Action {
+        if let Some(key_event) = event.as_key_event() {
+            // Handle events here that should not be passed on to the vim emulation handler.
+            match self.handle_key_events(key_event) {
+                Action::Handled => return Action::Handled,
+                _ => {}
+            }
+        }
+        if let Some(mouse_event) = event.as_mouse_event() {
+            match self.handle_mouse_events(mouse_event) {
+                Action::Handled => return Action::Handled,
+                _ => {}
+            }
+        }
+        Action::Pass
+    }
+
+    fn handle_key_events(&mut self, key: KeyEvent) -> Action {
+        let changed = match key.code {
+            KeyCode::Up => self.tree_state.key_up(),
+            KeyCode::Char('k') => self.tree_state.key_up(),
+            KeyCode::Down => self.tree_state.key_down(),
+            KeyCode::Char('j') => self.tree_state.key_down(),
+            KeyCode::Left => self.tree_state.key_left(),
+            KeyCode::Char('h') => self.tree_state.key_left(),
+            KeyCode::Right => self.tree_state.key_right(),
+            KeyCode::Char('l') => self.tree_state.key_right(),
+            KeyCode::Enter => self.tree_state.toggle_selected(),
+            _ => false,
+        };
+        if changed {
+            return Action::Handled;
+        }
+        Action::Noop
+    }
+
+    fn handle_mouse_events(&mut self, mouse: MouseEvent) -> Action {
+        let changed = match mouse.kind {
+            MouseEventKind::ScrollDown => self.tree_state.scroll_down(1),
+            MouseEventKind::ScrollUp => self.tree_state.scroll_up(1),
+            MouseEventKind::Down(_button) => self
+                .tree_state
+                .click_at(Position::new(mouse.column, mouse.row)),
+            _ => false,
+        };
+        if changed {
+            return Action::Handled;
+        }
+        Action::Noop
+    }
 }